Essential Oil Poisoning

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  • See also:

    Poisoning – acute guidelines for initial management
    Hydrocarbons Poisoning
    Eucalyptus oil Poisoning
    Camphor Poisoning
    Salicylates Poisoning

    Key points

    1. Mucous membrane irritation and gastrointestinal symptoms usually develop first, followed by CNS depression which increases the risk of aspiration pneumonitis
    2. Aspiration pneumonitis is a risk from both the essential oil and from hydrocarbons or emulsifiers that are added to many preparations
    3. Symptoms are specific to the type of essential oil. Contact poisons information for advice if specific ingestant is known

    For 24 hour advice, contact the Poisons Information Centre 13 11 26


    • Essential oils are a common household product used for medicinal, aromatic, cleaning and other purposes
    • Common essential oils include lavender, tea tree, nutmeg, sage, peppermint, wintergreen (see Salicylates Poisoning), fennel, geranium, lemon myrtle, thuja, woodworm, eucalyptus oil (see Eucalyptus oil Poisoning) and clove
    • Toxicity depends on the dose and the essential oil ingested
    • Toxicity can occur from the essential oil itself along with the hydrocarbons (see Hydrocarbon Poisoning) or emulsifiers added to many of the preparations

    Essential oils mimic other fat soluble drugs. They are well absorbed through mucous membranes and the skin and are excreted unchanged or as hepatic metabolites via lungs, urine, faeces and skin. Following ingestion, onset of symptoms (including rapid onset of CNS symptoms) is usually within one hour. Signs of aspiration usually appear immediately, but can be delayed up to 6 hours. Biochemical abnormalities following large ingestions may take 10 hours to occur

    Dose related toxicity

    • Essential oil concentrations range from 1-20%. 
    • Volumes of 5-15 mL are likely to cause toxicity in adults
    • Smaller Ingestions of 2-3 mL of some essential oils have been associated with toxicity in children
    • Signs of toxicity include mucous membrane irritation and gastrointestinal symptoms with possible CNS depression

    Children requiring assessment

    • All patients with deliberate self-poisoning or significant accidental ingestion
    • Any symptomatic patient
    • Ingested dose >5 mL
    • Any patient whose developmental age is inconsistent with accidental poisoning as non-accidental poisoning should be considered

    Risk assessment


    Intentional overdose or accidental

    • Stated or likely dose taken
    • Exact name of oil and amount/volume taken
    • Preparation type and % concentration, co-ingestants, eg paracetamol                  


    CNS: CNS depression (any change in mental state is significant), vertigo, dizziness, ataxia, seizures
    CVS:  Bradycardia,  hypotension
    Respiratory: Aspiration pneumonitis (gagging, choking, persistent coughing)
    GIT: Nausea, vomiting, diarrhoea. Hepatotoxicity is associated with  clove oil and pennyroyal oil ingestion
    Other: Mucous membrane irritation and numbness, dermal irritation, chemical conjunctivitis and corneal scarring have been reported 

    Specific oils and associated clinical manifestations

    Essential Oil

    Clinical manifestations

    Requires urgent discussion with toxicologist

    Large ingestions can have hepatotoxicity similar to paracetamol poisoning, renal failure, DIC, inhalational pneumonitis, coma


    Nausea, vomiting, seizure activity, pulmonary oedema


    Allergic contact cheilitis


    CNS depression, ataxia, photosensitiser that promotes hyperpigmentation, contact dermatitis

    Lemon myrtle

    Skin irritation and corrosion


    hallucinations, coma

    Requires urgent discussion with toxicologist

    Nausea, vomiting, abdominal pain, lethargy, agitation, dizziness and weakness. Large ingestions can have hepatotoxicity similar to paracetamol poisoning, renal failure, DIC, coma

    (Wormwood plant of the cedar family)

    Multiple tonic-clonic seizures

    (98% Methyl Salicylate)

    Nausea, vomiting, tinnitus, vertigo, hyperventilation, seizures. A dose as small as 1-2 mL can be toxic (see Salicylates Poisoning)


    Acidosis, acute renal failure, respiratory acidosis, rhabdomyolysis, visual alterations, delirium, restlessness, paranoia, tremor, seizures 


    See Eucalyptus Oil Poisoning

    Always check for Medicalert bracelet in any unconscious patient, or any other signs of underlying medical condition (fingerprick marks etc)


    Asymptomatic children with small ingestions do not usually require investigation

    In all children, consider:

    • Chest X-ray and blood gas if signs of aspiration pneumonitis
    • UEC and LFT in patient with significant illness, large ingestions or with clove oil/pennyroyal ingestions
    • Paracetamol level in all intentional overdoses

    Acute Management

    1. Resuscitation

    • Standard procedures and supportive care
    • Aspiration/chemical pneumonitis is managed supportively with oxygen and bronchodilators and may require non-invasive ventilation or intubation if severe
    • Fever is common following aspiration with pneumonitis. Antibiotics should be withheld until there is objective evidence of bacterial infection. Corticosteroids and prophylactic antibiotics are not indicated

    2. Decontamination 
    Charcoal is contraindicated due to risk of aspiration and due to the fact essential oils are rapidly absorbed.

    • Specific treatments: Consider NAC for significant clove oil, pennyroyal or halogenated hydrocarbon poisoning, discuss with poisons/toxicologist
    • Eye irritation management: Routine eye irrigation, however may require a longer duration of irrigation (oily substances).  Persistent eye symptoms should have ophthalmology review
    • Dermal exposure: Decontaminate area with soapy water, symptomatically treat any dermatitis/skin irritation

     Ongoing care and monitoring

    • Asymptomatic children with significant exposure (>5 mL) and normal vital signs including GCS, should be observed for 4 hours post exposure before discharge
    • Patients with respiratory or CNS symptoms should be admitted for a longer period of observation +/- supportive care.
    • Enhance elimination: ineffective
    • Antidote: Nil

    Consider consultation with local paediatric team when

    Admission should be considered for all adolescents with an intentional overdose

    Consult Victorian Poisons Information Centre 13 11 26 for advice

    Consider transfer when

    A child has significant CNS depression,  seizures or respiratory compromise as these children usually require ongoing management in a paediatric intensive care unit 

    For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services.

    Consider discharge when

    Normal GCS
    Period of observation as above

    Assessing risk and connecting to community services

    • Prior to discharge, adolescents who present with deliberate ingestions need a risk assessment regarding the likelihood of further ingestions or other attempts to self-harm
    • Assessment of other drug and alcohol use should also be undertaken
    • If, after risk assessment, it is deemed safe to discharge the child or adolescent from hospital, but ongoing mental health or drug and alcohol needs are identified, they should be linked with appropriate services (see links below for services in the State of Victoria)

    Discharge information and follow-up:

    Parent Information: Poisoning prevention for children
    Prevention of poisoning (Victorian Poisons Information Centre)

    Poisons Information Centre: phone 13 11 26

    Mental Health, Drug and Alcohol Services



    Last Updated July 2021


    Reference List

    1. TOXINZ Australia, DHHS. Essential Oil Blends (viewed 14 April 2021).
    2. Austin Clinical Toxicology Service Guideline. Hydrocarbons and Essential Oils. (viewed 14 April 2021).
    3. Therapeutic Guidelines. Essential Oil poisoning. (viewed 14 April 2021).
    4. Lee, K et al. Essential oil exposures in Australia: analysis of cases reported to the NSW Poisons Information Centre. Medical of Journal Australia. 2020. 212(3), p132-133.